TUI has no search/filter for tools, resources, prompts, or skills lists

Problem

The web client's tool/resource/prompt controls provide a search input to filter long lists (clients/web/src/components/groups/ToolControls/ToolControls.tsx), but the TUI's equivalent tabs (clients/tui/src/components/{ToolsTab,ResourcesTab,PromptsTab,SkillsTab}.tsx) have no search or filter capability at all. When connected to a server exposing many tools/resources, TUI users have to scroll through the entire list with no way to narrow it down.

Proposal

Add a lightweight text-filter input to each of the TUI's list-based tabs (e.g. triggered by /, consistent with common TUI conventions), filtering visible items by name/title as the user types.

Why it matters

This is a straightforward parity gap between the web and TUI clients, found during a code-level review of v2.7.0. It doesn't require any new protocol support -- it's a self-contained TUI-side UX addition.

Suggested labels: enhancement, tui